There's little evidence that this has led to widespread voter fraud, but it has raised concerns that the system is vulnerable.

Election officials say one problem is that Americans move around a lot. And when they do, they seldom alert the local election office that they've left.

Ben Skupien, a registered voter who now lives in Northern Virginia, is pretty typical. He has moved repeatedly over the years and says he's probably registered to vote in about a half-dozen states.

"The assumption, I would think, is that they would do the courtesy of letting the other states know that if you're registered with a new state, [the old registration] would no longer apply," said Skupien.

In fact, states seldom share such information. The Pew study found that almost 3 million people are registered to vote in more than one state.

Voters also die, which leads to another problem, says Linda Lamone, who runs Maryland's elections.

"If a John Smith lives in Maryland and goes to another state, say on vacation, and dies," Lamone said, "the law of the state where John Smith dies dictates whether or not the Maryland vital statistics people can share that information with me."

And even when they do — or if a person dies in-state — there's often a delay before election officials are alerted. It's also not always clear that the individual on the death certificate is the same one who's registered to vote. Election officials still have to do a lot more digging to avoid accidentally taking someone off the rolls who is very much alive.

Washington Secretary of State Sam Reed says it's amazing how many times his state has come across names on the voter rolls that appear to be the same person, but turn out not to be.

"We've even had cases, in very small counties, people [with the] same name and same birth dates," added Reed.

He said that has led to inaccurate reports that "dead" people are voting. He admits there have been a few cases in his state where widows or widowers have cast ballots for former spouses, but he said such fraud is very rare.

Still, election officials say it's important that the public have confidence in the system.

So Washington and seven other states — Oregon, Colorado, Delaware, Maryland, Virginia, Utah and Nevada — are joining a pilot program to share more voter information and other databases, to try to make their lists more accurate.

David Becker, director of election initiatives at Pew, which organized the project, said he hopes to have the program implemented in time for November's general election.

"What this system will do is it will take in data from the states who choose to participate, specifically motor vehicles data and voter registration data, and it will be matched, along with some data that many states use already, like national change of address data from the Postal Service," said Becker.

The data will be matched with other government databases as well, such as death records from the Social Security Administration.

Becker thinks that should help states weed out duplicates and mistakes more quickly and accurately. He said the program will also allow states to identify some of the more than 50 million Americans who are eligible to vote but aren't registered.

Election officials can then contact them and encourage them to sign up.

It all sounds great to Lillie Coney of the Electronic Privacy Information Center, a research group in Washington, D.C. But she and other privacy advocates say they'll be watching closely to make sure all this new data-sharing actually leads to more accurate voter rolls.

"We do know that there are a lot of people who want to believe that that in fact will be the case, but we want to see the numbers," said Coney.

Coney recalled another data-matching program in Florida where legitimate voters were confused with convicted felons and mistakenly removed from the rolls.

Becker said no one's name will be deleted automatically. Officials are required by law to try to contact the voter first.

Copyright 2013 NPR. To see more, visit http://www.npr.org/.

Transcript

RENEE MONTAGNE, HOST:

Health care will be part of the debate this season. So will the mechanics of the election itself.

A new report finds almost two million dead people are currently registered to vote. Twenty-four million registrations are either invalid or inaccurate. There's little evidence this has led to widespread fraud, but it has raised concerns that the system is vulnerable.

NPR's Pam Fessler reports on an effort to clean things up.

PAM FESSLER, BYLINE: Here's the problem: Like many Americans, Ben Skupien of northern Virginia has moved repeatedly. Over the years, he says, he's registered to vote in about a half-dozen states.

BEN SKUPIEN: The assumption, I would think, is that they would do the courtesy of letting the others states know that if you're registered with a new state, then other one would no longer apply.

FESSLER: Nina Horowitz thought pretty much the same thing when she moved to Washington, D.C. from Illinois.

NINA HOROWITZ: Maybe I assumed that if I registered someplace else, it would sort of nullify the other registration. But that's probably too much to expect. I doubt the states actually talk to each other about it.

FESSLER: And about that, Horowitz is correct. States share some information, but not a lot. A new study by the Pew Center on the States finds that almost three million people are registered in more than one state. Election officials say it's hard to keep up with one in eight Americans moving each year. They also have to keep up with voter deaths. Linda Lamone runs elections for the state of Maryland.

LINDA LAMONE: If a John Smith lives in Maryland and goes to another state - say, on vacation - and dies, the law of the state where John Smith dies dictates whether or not the Maryland vital statistics people can share that information with me.

FESSLER: And even when they do - or if a person dies in-state - it's also not always clear that the individual on the death certificate is the same one registered to vote. Election officials have to do a lot more digging to avoid accidentally taking someone off the rolls who's very much alive.

SAM REED: You can never assume just because something comes up in the computer it's correct.

FESSLER: Sam Reed is the long-time Secretary of State for Washington State. He says it's amazing how many times they found names that appear to be the same person, but turn out not to be.

REED: And we've even had cases, in very small counties, people same name and same birth dates.

FESSLER: Which, he says, has led to inaccurate reports that dead people are voting. Reed admits there are cases in his state where widows or widowers have cast ballots for former spouses, but he says such fraud is very rare. Still, election officials say it's important that the public have confidence in the system. So Washington and seven other states are joining a pilot program to share more voter information and other databases to try to make their lists more accurate.

DAVID BECKER: What this system will do is it'll take in data from the states who choose to participate, specifically motor vehicles data and voter registration data.

FESSLER: David Becker, director of election initiatives at Pew, which has organized the project.

BECKER: And it will be matched, along with some data that many states use already, like national change of address data from the Postal Service.

FESSLER: And other information to help them weed out duplicates and mistakes. Becker says the program will also allow help states to identify some of the 50 million-plus Americans who are eligible to vote but aren't registered, so election officials can then contact them and encourage them to sign up. It all sounds great, says Lillie Coney of the Electronic Privacy Information Center, a research group in Washington, D.C., but she and other privacy advocates say they'll be watching closely to make sure that all this data-sharing actually leads to more accurate voter rolls.

LILLIE CONEY: We do know that there are a lot of people who want to believe that that, in fact, will be the case, but we want to see the numbers.

FESSLER: She recalls another data-matching program in Florida, where legitimate voters were confused with convicted felons and mistakenly removed from the rolls. Becker of Pew says no one's name will be deleted automatically, that officials are required by law to try to contact the voter first. Pam Fessler, NPR News, Washington. Transcript provided by NPR, Copyright NPR.